Spraying device for lining the interior of small diameter pipes



Ju ly 8, 1958 2,842,095

R. BNER SPRAYING DEVICE FOR LINING THE INTERIOR OF SMALL DIAMETER PIPES Filed Kay 5; 1956 2 Sheets-Sheet 1 Robert Leibner INVENTOR.

BY M40 (puny 3% g/IZ July 8,' 1958 v R. LEIBNER SPRAYING DEVICE FOR LINING THE INTERIOR 0F SMALL DIAMETER PIPES Filed May 5, 1956 2 Sheets-Sheet 2 Robert Le/bner IN V EN TOR. ma BY Q.

my fiML SPRAYING DEVICE FQRLINING THE INTERIOR OF SMALL DIAMETER PIPES Robert Leibner, Kings Park, N. Y.

Application May 15, 1956, SerialNo. 584,992

1 Claim. (Cl. 118-306) T his invention relates in general to new and useful improvements in spraying equipment, and more particularly to an improved spray gun for spraying the internal surfaces of pipe and the like.

in order that pipe may not deteriorate in its interior, it is necessary that a suitable coating be applied thereto. This is particularly true of boiler tubes. Heretobefore the coating compound or material has been placed on the internal surfaces of boiler tubes and other pipes by means of a brush which operates from a turbine. The brush assembly requires one man for controlling the operation of the turbine and another man for supplying the application of the coating material to the brush. Further, because of the brushing action and the dual control the coating applied has had a tendency to be uneven which is undesirable.

It is therefore the primary objectof this invention to provide an improved spraygun which is so constructed whereby it may be pulled through a pipe, such as a boiler tube, and which will spray an even coating of a coating material on the internal surfaces of such pipe.

Another object of this invention is to provide, an improved spray gun for coating internal surfaces of pipes and the like, the spray gun being of extremely simple construction and containing no moving parts thereby having a very long life and at the same time being economical to manufacture.

A further object of this invention is to provide an improved spray gun for coating interiors of pipes, the spray gun being so constructed whereby operation thereof by one man is possible thus permitting the cost of spraying the interiors of pipe to be greatly reduced.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a fragmentary sectional view taken through a boiler and shows the spray gun which is the subject of this invention partly positioned in one end of the boiler tube, an intermediate portion of the boiler tube being broken away;

Figure 2 is an enlarged fragmentary sectional view taken through the boiler tube of Figure 1 and shows the spray gun positioned Within the boiler tube in operation;

Figure 3 is an enlarged fragmentary sectional view similar to Figure 2 and taken at right angles thereto showing further the details of the relationship of the spray gun with respect to the boiler tube, there also being illustrated the specific details of the spray gun, the view being taken substantially upon the plane indicated by the section line 3-3 of Figure 2;

Figure 4 is an enlarged fragmentary transverse sectional view taken substantially upon the plane indicated by the section line 4-4 of Figure 2 and shows the general details of a spray nozzle assembly of the spray gun rates atent ice 2 and the relationship of a guide block thereof with respect to the boiler tube being coated; and

Figure 5 is anjenlarged fragmentary transverse sectional view taken substantially upon the plane indicated by the section line 55 of Figure 3 and shows the relationship of the valves of the spray gun with respect to the boiler tube.

Referring now to the drawings in detail, it will be seen that there is illustrated in Figure 1 a fragmentary portion of a boiler which is referred to in general by the reference numeral 10. The boiler 10 includes suitable headers 12 which have extending therebetween a boiler tube 14. It is to be understood that the boiler tube 14 is only an example of the application of the present invention. Positioned in one end of the boiler tube 14 is the spray gun which is the subject of this invention, the spray gun being referred to in general by the reference numeral 16.

Referring now to-Figure 3 in particular, it will be seen that the spray gun 16 includes an elongated. guide block 18 which is circular in cross-section and which is of a size to fit within the boiler tube 14 for the purpose of guiding the spray gun 16 during its travel through the boiler tube 14 and for centering the spray gun in with respect to the longitudinal axis of the boiler tube 14. If desired the guide block may be hollow.

Extending through the guide block 18 in the center thereof is a bore 20 which continues through a boss 22 projecting from the rear. end of the guide block 18. Seated within the bore Ztl and suitably secured to the guide block 18 is an air supply pipe 24. Connected to the rear end of the air supply pipe 24 is a control valve 26 which has an operating handle 23. Connected to the rear end of the control valve 26 is an air supply line 3-8 which is preferably flex ible and in the form of a hose.

The guide block 13 is provided with a second longitudinal bore 32 which is spaced radially from the bore 20. Extending through the bore 32 and suitably secured to the guide block 18 is a coating material supply pipe 34. The rear part of the coating material supply pipe 34- is connected to the air supply pipe 24 by means of a strap 36. Secured to the rear end of the coating material supply pipe 3 is a control valve 33 having an operating handle 40.

Suitably connected to the rear end of the control valve 38 is a coating material supply line 42 which is flexible and preferably in the form of a hose. The opposite end of the coating material supply line 4-2 is connected to a shutoff valve 44- which is mounted on the lower part of the coating material supply tank 46. It is to be understood that the opposite end of the air supply line St? is to be connected to a suitable compressed air source (not shown).

Mounted on the forward ends of the air supply pipe 24 and the coating material supply pipe 34 is a spray nozzle assembly which is referred to in general by the reference numeral 48. The spray nozzle assembly 43 includes an air nozzle 50 which is disposed in the exact center of the boiler tube 14 or other pipe being coated by means of the guide block 18. The air nozzle oil is secured on the forward end of the air supply pipe 24. Also secured to the forward end of the air supply pipe 24 by means of the air nozzle 5% is a suitable support bracket 52. The support bracket 52 carries an L-shaped coating material pick-up tube 54 which includes a lower horizontal portion 56 connected to the forward end of the coating Ina-- terial supply pipe 34, and an upright portion 58. The upright portion 58 is open ended and terminates slightly below an outlet opening 6!) in the air nozzle From the foregoing description of the spray gun lo, it will be seen that all of the components thereof are so arranged whereby they will fit within the pipe or boiler tube, such as the boiler tube 14 for which the spray gun 16 is intended. Thus all parts of the spray gun 16 will be disposed within the area defined by projecting the cross-section of the guide block 18. This includes the control valves 26 and 38.

In the operation of the spray gun 16, the spray gun 16 is positioned in one end of a pipe to be coated with the air supply line 30 and the coating material supply line 42 extending through such pipe. The spray nozzle assembly 48 is positioned adjacent the one end of the pipe. Prior to this, the control valves 26 and 38 are opened the desired amount. This amount can be determined by prior experience. Next compressed air is supplied to the spray nozzle assembly 48 and then the shut-off valve 44 of the coating material supply tank 46 is opened. Since the compressed air exiting from the air nozzle 31 will create a vacuum in the pick-up tube 44, the coating material, which is liquid, will be drawn out of the pick-up tube 54 and will be sprayed in a conical pattern by the compressed air. predetermined rate to provide the desired thickness of coating. Inasmuch as the coating is applied under pressure, it will be seen that the penetration of the coating is very good and is in fact better than that obtainable with a brush method. Since all of the controls for the spray gun 16 are extremely simple and at one end of the pipe being coated, it will be readily apparent that the spray gun 16 may be operated by a single operator. Further, it will be readily apparent that the spray gun 16 is of a lasting type inasmuch as it contains no moving parts.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

A spray gun for lining the interior of small diameter The spray gun 16 is drawn through the pipe at a pipes, such as boiler tubes, said spray gun comprising an elongated solid guide block of a circular cross-section, the cross-section of said guide block corresponding generally to the interior cross-section of the pipe to be lined whereby said guide block is guided by the pipe in its passage therethrough, an air supply pipe extending through and supported by said guide block, a coating material supply pipe extending through and supported by said guide block adjacent said air supply pipe, a spray nozzle assembly carried by said air supply pipe and said coating material supply pipe adjacent said guide block and in advance thereof, said spray nozzle assembly including an air nozzle and a coating material pick-up tube, said air nozzle being centered relative to said guide block whereby coating material is evenly supplied to an interior of a pipe to be lined, a support on said air nozzle engaging and supporting said pick-up tube relative to said air nozzle, flexible supply lines connected to said air supply pipe and said coating material supply pipe, said supply lines also forming a means for moving said guide block and said spray nozzle through a pipe being lined, separate control valves on said airv supply pipe and said coating material supply pipe, said control valves being disposed within an area defined by a longitudinal projection of said guide block whereby said valves clearly pass through the pipe being lined, said control valves being disposed rear- Wardly of said guide block and protected from said spray nozzle by said guide block.

References Cited in the file of this patent UNITED STATES PATENTS 1,326,483 Doran Dec. 30, 1919 2,048,912 Zeska et al July 28, 1936 2,353,951 Wood et al July 18, 1944 2,403,994 Paynter July 16, 1946 2,428,292 Queen Sept. 30, 1947 2,520,397 Green Aug. 29, 1950 2,715,383 Yates Aug. 16, 1955 

